1. Field of the Invention
The present invention relates to information handling systems and more particularly to information handling systems and more particularly to information handling systems which communicate with an Internet small computer system interface (iSCSI).
2. Description of the Related Art
As the value and use of information continue to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
In server type information handling systems and interact protocol (IP) based storage controllers, it is known to implement load balance mechanisms to provide port redundancy and load balancing for network traffic and storage traffic over an IP type communication system. It is known for egress traffic from a host system is load balanced across a plurality of team members with equal priority using a hashing algorithm. For each session that is initiated, a load balancing system (e.g., load balancing software) analyzes usage of the host's physical adapters and establishes the session on one of the physical adapters without considering the physical location of the end node in the network. Basically known load balance mechanisms are substantially solely based on the IP reachability (i.e., is the physical adapter available via an IP address).
However, many known network systems comprise a plurality of communication paths to provide redundancy in the network. With these network systems, a load balancing mechanism does not always provide the shortest path between the nodes. In this situation, the load balancing may not yield the best achievable performance for communication within the network system.
One such network system is identified under the trade designation Dell EqualLogic. Referring to FIG. 1, labeled Prior Art, with a Dell EqualLogic network system array, a plurality of ports of the server type information handling system controller are coupled to two different switches that are then coupled together via an Inter switch link (ISL) which may be a Dell EqualLogic type ISL. Such a topology thus provides redundant paths and services are still available in case of a switch failure. With such a system, a host integration toolkit (such as the EqualLogic Host Integration Tools (HIT) toolkit) contains a connection manager (such as the EqualLogic Host Connection Manager (EHCM)) that can automatically establish iSCSI connections. However, one issue users may encounter is that the connection manager does not have knowledge regarding to which switch fabric each array port is coupled. Thus, with a system having two switches there is only a 50% probability that each connection goes through a particular ISL link. Not having knowledge regarding or being in control to which switch fabric an array port is coupled provides a number of challenges.
For example, one issue relates to bandwidth of the network system. More specifically, in known network systems it is possible that established communication sessions may communicate via a longer ISL link path. The longer ISL link path can then become a bottleneck to the system or may induce a high latency in a configuration with a large number of iSCSI connections (e.g., in a system which includes multiple servers connected to multiple arrays). Improving ISL bandwidth can become even important when performing input/output (I/O) consolidation operations. Another issue relates to I/O errors within the network system. A switch failure can cause the ISL to fail which can then cause I/O communications from both paths to fail. This may result in transient I/O errors being reported back to the operating system (OS) and applications. Some applications can manage the errors and retry the communication, but some cannot.